Multiple pulse jet burner with cooling means



June 1, 1965 F. HAAG 3,136,331

' MULTIPLE PULSE JET BURNER WITH COOLING MEANS Filed July 24, 1962 mum r0? Franz HAAG 7 4.2444 1 Jfr/Q,

In: Wrap/w y United States Patent 3,186,381 MULTIPLE PULSE JET BURNER WITH COOLING MEANS Franz Haag, Plochingen (Neckar), Germany, assignor to Junkers & Co. G.m.b.]l-I., Wcrnau (Neckar), Germany Filed July 24, 1962, Ser. No. 212,048 Claims priority, application Germany, Aug. 2, 1961, J 20,393 11 Claims. (Cl. 12224) The present invention relates to burners in general, and more particularly to improvements in burners of the type known as pulse jet or resonance duct burners. Still more particularly, the invention relates to a pulse jet burner which is suited for heating of water and other types of liquids.

It is one of the objects Glf my invention to provide a very simple and comparatively inexpensive burner with good efiiciency.

Another object of the invention is to provide a burner wherein the fluid which requires heating may be used for cooling the burner walls so that the heating operation may be carried out in two stages.

A further object of the invention is to provide a novel cooling system for a pulse jet burner which is constructed and assembled in such a way that each wall of the burner, including such wall or walls which are not accessible from the outside, may be cooled in a very simple and highly efiicient manner.

An additional object of the invention is to provide a ethod of forming the wall of a pulse jet burner with one or more coolant-conveying internal channels. Still another object of the instant invention is to provide a pulse jet burner wherein such specially formed Wall or walls separate the individual fuel combustion chambers from each other.

A concomitant object of the invention is to provide a greatly simplified composite multi-chamber pulse jet burner.

With the above objects in view, the invention resides in the provision of a pulse jet burner which comprises a hollow tubular mantle and substantially radially extending wall means accommodated in and subdividing the interior of the mantle into a plurality of substantially segmental combustion chambers each of which is provided with an inlet for the combustible mixture and an outlet for products of combustion. In accordance with another feature of my invention, the burner comprises means for cooling the wall structure in the mantle, and this cooling means may assume the form of one or more internal channels defined by the wall means and separated from the combustion chambers so that water or another coolant admitted through the inlet of the channel or channels cools the wall means and may thereupon flow about the mantle to be heated to requisite temperature.

The wall means may assume the form of pairwise arranged plates having portions Which are in full or partial face-to-face abutment with each other and substantially trough-shaped portions which are mirror symmetrical with respect to each other and which together define one or more coolant-conveying channels.

The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The invent-ion itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following detailed description of certain specific embodiments with reference to the accompany-ing drawings, in which:

FIG. 1 is an axial section through a pulse jet burner which embodies one form of my invention; I

FIG. 2 is a transverse section as seen in the direction of arrows from the line IIII of FIG. 1;

FIG. 3 is a side elevational view of a wall or partition which forms part of the burner shown in FIGS. 1 and 2,

the view of FIG. 3 being taken in the direction of arrows as seen from the line III-III of FIG. 1; and

FIG. 4 is a fragmentary sect-ion through a pair of cooperating walls which form part of a slightly different burner.

Referring now in greater detail to the drawings, and first to FIG. 1, there is shown a burner of the pulse jet or resonance duct type which comprise a tubular mantle 3 here shown as a hollow cylinder of heat-resistant metallic material, and this mantle accommodates a specially constructed and mounted wall structure 4, 5 which subdivides its interior into a pair of segmental combustion chambers 1, 2 each of which assumes a semicylindrical shape because the wall structure extends radially (i.e., diametrally) of and in the axial direction of the mantle. The configuration of the chambers 1, 2 is shown in FIG. 2, and it will be noted that these chambers have inlets 1a, 2a respectively connected with supply pipes 17, 18 through which a combustible mixture may enter the burner to be ignited in the manner as known in the art of conventional pulse jet burners, whereupon the products of combustion developing during ignition of combustible mixture in the chambers 1, 2 are respectively evacuated through outlets 1b, 2b and enter resonance duct 19, 20 provided at the lower axial end of the mantle 3, as viewed in FIG. 1. The pipes 17, 18 are respectively provided with substantially radially extending fuel admitting nozzles 16, 15 so that the combustible mixture is formed in these pipes downstream of the respective nozzles when the fuel is mixed with air entering through the upper ends of the pipes 17, 18, as viewed in FIG. 1. The means for supplying air to the pipes 17, 18 and the means for supplying gaseous, liquid or comminuted solid fuel to the nozzles 15, 16 form no part of this invention and, therefore, are not shown in the drawings.

In accordance with an important feature of my invention, the wall structure 4, 5 is cooled by water or another suitable coolant and, to this end, the wall structure defines a continuous internal channel 9 which is separated from the combustion chambers 1, 2 and whose inlet 9A (at or near to the upper axial end of the mantle 3, as viewed in FIG. 1) is connected to a coolant admitting pipe 14 through which cold water is pumped from a suitable source in a direction indicated by the arrow so that a stream of water flows continuously through the channel 9 to cool the wall means 4, 5 and to enter the intake end of a coolant receiving pipe 12 which is connected to the outlet 9B of the channel at or near to the lower axial end of the mantle 3. In the embodiment of FIGS. 1 to 3, coolant entering through the pipe 14 is the medium which is being heated by products of combustion developing in the chambers 1, 2 and, therefore, the pipe 12 is coiled about the mantle to make sure that the fluid discharged at 13 is heated to requisite temperature. In other words, the stream of coolant entering at 14 is subjected to a first heating action while flowing along the channel 9, and thereupon to a second heating action while flowing through the coiled pipe 12.

The wall structure comprises a pair of walls 4 and 5 whose marginal portions 10, 11 are secured to the inner side of the mantle 3 by welding seams extending in parallelism with and located at the diametrically opposite sides of the burner axis. It will be seen that the walls 4, 5 assume the form of plates having flat portions 8, 8a which are in at least partial face-to-face abutment with and which are welded or otherwise bonded to each other, and substantially trough-shaped portions 6, 7 which together define a leak proof channel 9. It will be noted that each trough-shaped portion is of substantially semicircular cross-section so that the cross-section of the conduit formed by these portions is circular. FIG. 3 shows that the portion 7 of the wall meanders back and forth substantially diametrally of the mantle 3 and between the marginal portions It), 11. The trough-shaped portion 6 of the wall 4 is mirror symmetrical to the portion 7.

In accordance with my method, the Wall structure may be formed as follows: In the first step, the walls 4, 5 are placed face-to-face and are welded together along their respective portions 3 and 8a. In the next step, a pressure fluid is admitted between the portions 6 and 7 to deform the walls and to impart to the portions 6, 7 the shape of troughs.

FIG. 4 illustrates a portion of a modified wall structure 134, 105 which may be utilized in the burner of FIG. 1. The wall portions 108, 108a are at least partially welded to each other and the wall portions 1%, 197 define a coolant-conveying channel 109 of oval cross-section.

The burner of my invention may be utilized in connection with combustible mixtures which preferably comprise gaseous fuel, but it will be readily understood that the burner is equally useful for operation with liquid, pulverulent or comminuted solid fuel-s. It is equally possible to subdivide the interior of the mantle 3 into three, four or more segmental combustion chambers without in any way departing from the spirit and scope of my invention. Such modifications are so obvious that they can be readily comprehended without additional illustrations. 7

For example, by providing a second radially extending wall structure at right angles to the structure 4, 5 or 104, E05, the internal space of the mantle 3 may be subdivided into four separate combustion chambers.

Of course, it is not necessary to form the mantle 3 as a onepiecestructure since it is equally possible to assemble this mantle of two or more sections or shells. Thus, and referring to FIG. 2, the composite multi-chamber burner of my invention may be assembled by Welding .the wall 4 to a first semicylindrical shell corresponding to the right-hand half of the mantle 3, by welding the wall 5 to a second semicylindrical shell corresponding to the left-hand half of the mantle 3, and by thereupon welding the wall portions 8, 8a to each other. It is often sufiicient if certain isolated zones of the wall portions 8, 8a are connected by welding as long as they insure that the wall portions 6, 7 form a coolant-conveying channel.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by apply current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic and specific aspects of this inven tion and, therefore, such adaptations should and are intended to be comprehended within the meaning and range a of equivalence of the following claims.

What is claimed as new and desired to be secured by Letters Patent is: V

1. A pulse jet burner arrangement, comprising a hollow tubular mantle; substantially radially extending wall means provided in and subdividing the interior of said mantle into a plurality of substantially segmental combustion chambers, each of said chambers having inlet means comprising an inlet pipe arranged to deliver a supply of air to the respective chamber and a fuel pipe connected to said inlet pipe and arranged to deliver fuel thereto so that thefuel mixes with the air in said inletu pipe to form a combustible mixture which then enters the respective chamber, and outlet means comprising a resonance duct through which products developing during combustion of such mixture are evacuated from the red mentioned inlet means; and coolant receiving means connected with said last mentioned outlet means.

2. A pulse jet burner arrangement, comprising a hollow tubular mantle; substantially radially extending Wall means provided in and subdividing the interior of said mantle into a plurality of substantially segmental combustion chambers, each of said chambers having inlet means comprising an inlet pipe arranged to deliver a supply of air to the respective chamber and a fuel pipe connected to said inlet pipe and arranged to deliver fuel thereto so that the fuel mixes with the air in such inlet pipe to form a combustible mixture which then enters the respective chamber and outlet means comprising a resonance duct through which products developing during combustion of such mixture are evacuated from the respective chamber, said wall means having substantially plate-like first portions which are in at least partial faceto-face abutment with each other and second portions which define continuous coolant-conveying channel means separated from said chambers and said channel means having inlet and outlet means; coolant admitting means connected with said last mentioned inlet means; and coolant receiving means connected with said last mentioned outlet means, said coolant receiving means comprising a coiled pipe surrounding said mantle so that a coolant admitted through the inlet means of said channel means is being heated first while passing through said channel means and thereupon while passing through said pipe.

3. A pulse jet burned arrangement, comprising a hoilow tubular mantle; substantially radially extending pairwise arranged Wall means provided in and subdividing the interior of said mantle into a plurality of substantially segmental combustion chambers, each of said chambers having inlet means comprising an inlet pipe arranged to deliver a supply of air to the respective chamber and a fuel pipe connected to said inlet pipe and arranged to deliver fuel thereto so that the fuel mixes with the air in said inlet pipe to form a combustible mixture which then enters the respective chamber and outlet means comprising a resonance duct through which products developing during combustion of such mixture are evacuated from the respective chamber, said wall means having first portions which are in at least partial face-to-face abutment with each other and second portions which define coolant-conveying channel means separated from said chambers, said channel means having inlet and outlet means; coolant admitting means connected with said last mentioned inlet means; and coolant receiving mean connected with said last mentioned outlet means.

4. A pulse jet burner arrangement, comprising a hollow cylindrical mantle; pairwise arranged Wall means provided in and extending substantially diametrally with respect to said mantle, said wall means having spaced marginal portionsdisposed at the opposite sides of the axis of and secured to said mantle soas to subdivide the interior 'of said mantle into a pair of substantially semicylindrical combustion chambers, each of said chambers having inlet means comprising an inlet pipe arranged to deliver'a supply of air to the respective chamber and a fuel pipe connected to said inlet pipe and arranged to deliver :fu'el thereto so that the fuel mixes with the air in said inlet pipe to form a combustible mixture which then enters the respective chamber; and outlet means c0mpris-- spective chamber, said wal-l means defining internal cool-' ant-conveying channel means separated from said chamhers and said channel meanshaving inlet and outlet means; coolant admitting means connected :Withsaid last ing a resonance duct throughwhich products developing during combustion of such mixture are evacuated from the respective chamber, said Wall means having substantially plate-like firstportions' which are in at least partial face-to-face abutment with each other and second por-- tion-swhich define continuous coolant conveying channel means of meandering shape, said channel means separated from said chambers and having inlet and outlet means; coolant admitting means connected with said last mentioned inlet "meanspand coolant receiving means connected with said last mentioned outlet means.

5. A burner as set forth in claim 4, wherein said channel means comprises sections extending substantially diametrally of said mantle and between the marginal portions of said wall means.

6. A pulse jet burner arrangement, comprising a hollow tubular mantle; substantially radially extending pairwise arranged wall means provided in and subdividing the interior of said mantle into a plurality of substantially segmental combustion chambers, said pairwise a ranged wall means having substantially plate-like first portions which are in at least partial face-to-face abutment with and connected to each other and free second portions spaced from each other so as to define continuous coolant conveying channel means separated from said chambers and having inlet and outlet means, said first portions being arranged to prevent leakage of coolant from said channel means, each of said combustion chambers having inlet means comprising an inlet pipe arranged to deliver a supply of air to the respective chamber and a fuel pipe connected to said inlet pipe and arranged to deliver fuel thereto so that the fuel mixes with the air in said inlet pipe to form a combustible mixture which then enters the respective chamber, and outlet means com prising a resonance duct through which products developing during combustion of such mixture are evacuated from the respective chamber; coolant admitting means connected with said first mentioned inlet means; and coolant receiving means connected with said first mentioned outlet means.

7. A pulse jet burner arrangement, comprising a hollow tubular mantle; substantially radially extending pairwise arranged wall means provided in and subdividing the interior of said mantle into a plurality of substantially segmental combustion chambers, each of said chambers having inlet means comprising an inlet pipe arranged to deliver a supply of air to the respective chamber and a fuel pipe connected to said inlet pipe and arranged to deliver fuel thereto so that the fuel mixes with the air in said inlet pipe to form a combustible mixture which then enters the respective chamber, and an outlet comprising a resonance duct through which products developing during combustion of such mixture are evacuated from the respective chamber, said wall mean-s having substantially plate-like portions which are in at least partial face-to-face abutment with and connected to each other and substantially trough-shaped portions which together define a continuous coolant-conveying channel, said channel being separated from said chambers and having an inlet and an outlet, said plate-like portions being arranged to prevent leakage of coolant from said channel mean-s; coolant-admitting means connected with the inlet of said channel; and

coolant receiving means connected with the outlet of said channel.

8. A burner as set forth in claim 7, wherein said troughshaped portions are of substantially semicircular cross section.

9. A burner as set forth in claim 7, wherein said trough-shaped portions are of substantially semielliptical cross section.

10. A pulse jet burner arrangement, comprising a hollow tubular mantle; pairwise arranged wall means provided in and subdividing the interior of said mantle into a plurality of separate combustion chambers each of said chamber-s having inlet means comprising an inlet pipe arranged to deliver a supply of air to the respective chamber and a fuel pipe connected to said inlet pipe and arranged to deliver fuel thereto so that the fuel mixes with the air in said inlet pipe to form a combustible mixture which then enters the respective chamber, and outlet means comprising a resonance duct through which products developing during combustion of such mixture are evacuated from the respective chamber, said pairwise arranged wall means having portions in at least partial faceto-face abutment with and connected to each other and substantially trough-shaped portions formed upon outward deformation of the remainder of said walls by fluid pressure, said trough-shaped portions defining leak-proof internal coolant-conveying channel means separated from said chambers and adapted to receive a fluid coolant to cool said wall means.

11. A burner as set forth in claim 10, wherein said channel means consists of a single continuous channel of meandering shape having sections extending substantially diametrally of said mantle, said channel having an inlet at one axial end and an outlet at the other axial end of said mantle.

References Cited by the Examiner UNITED STATES PATENTS 860,983 7/07 MacDonald 1226.6 1,982,075 11/34 Smith 165171 2,525,782 10/50 Dunbar 1584 2,628,471 2/53 Dunbar 35.6 2,795,104 6/57 Zinner 60--39.66

FOREIGN PATENTS 224,102 9/59 Australia.

885,247 12/61 Great Britain.

PERCY L. PATRICK, Primary Examiner.

MEYER PERLIN, JAMES W. WESTHAVER,

Examiners. 

1. A PULSE JET BURNER ARRANGEMENT, COMPRISING A HOLLOW TUBULAR MANTLE; SUBSTANTIALLY RADIALLY EXTENDING WALL MEANS PROVIDED IN AND SUBDIVIDING THE INTERIOR OF SAID MANTLE INTO A PLURALITY OF SUBSTANTIALLY SEGMENTAL COMBUSTION CHAMBERS, EACH OF SAID CHAMBERS HAVING INLET MEAN COMPRISING AN INLET PIPE ARRANGED TO DELIVER A SUPPLY OF AIR TO THE RESPECTIVE CHAMBER AND A FUEL PIPE CONNECTED TO SAID INLET PIPE AND ARRANGED TO DELIVER FUEL THERETO SO THAT THE FUEL MIXES WITHH THE AIR IN SAID INLET PIPE TO FORM A COMBUSTIBLE MIXTURE WHICH THEN ENTERS THE RESPECTIVE CHAMBER, AND OUTLET MEANS COMPRISING A RESONANCE DUCT THROUGH WHICH PRODUCTS DEVELOPING DURING COMBUSTION OF SUCH MIXTURE ARE EVACUATED FROM THE RESPECTIVE CHAMBER, SAID WALL MEANS DEFINING INTERNAL COOLANT-CONVEYING CHANNEL MEANS SEPARATED FROM SAID CHAMBERS AND SAID CHANNEL MEANS HAVING INLET AND OUTLET MEANS; COOLANT ADMITTING MEANS CONNECTED WITH SAID LAST MENTIONED INLET MEANS; AND COOLANT RECEIVING MEANS CONNECTED WITH SAID LAST MENTIONED OUTLET MEANS. 